Fabrication and characteristics of strontium barium niobate/ barium strontium titanate ceramics by powder−sol method
(Department of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China)
Abstract: Barium strontium titanate (Ba1−xSrxTiO3, BST) and strontium barium niobate (SrxBa1−xNb2O6, SBN) are important ferroelectric materials with excellent pyroelectric, dielectric properties and faster response time of infrared radiation. SBN/BST composite ceramics with different mole ratios of Nb and Ti were fabricated using a powder-sol (P-S) method with Nb2O5 fine powders suspended in the barium strontium titanate (BST in short) sol solution. The X-ray diffraction results indicate that three intermediate phases, i.e. TiO2, BaNb2O6 and SrNb2O6, are developed during the formation of SBN-BST. Powders obtained from dried gels are calcined at 800 ℃ for 3 h. The Ti2p spectra of only one spin-orbit doublet are observed, which indicates one 4+ chemical state in the composite ceramics. The binding energies of Nb element depend strongly on composition.
Key words: barium strontium titanate; strontium barium niobate; binding energy